Making particles collide with each other? Possible? (2.8)
Particles collision can be achieved with the molecular addon by pyroevil. There is a 2.80 port but you may have to do some digging to find it. Version of the addon I have for Blender 2.80 is 1.0.7 but I hear a 1.0.8 is out.
Where do I hear it, do you ask?

Here: https://blenderartists.org/t/addon-moleculars-physics/521682/255

Addon here:
https://github.com/scorpion81/Blender-Molecular-Script/releases

As for the shattering, there is a cell fracture addon provided with 2.80. I'm not sure how you'll manage to use it on particles, though.

You can try combining with the particles instance modifier. Worth giving it a shot. Or using animation nodes, maybe.